(1) Field of the Invention
This invention relates to a control apparatus for controlling transfer of semiconductor wafers, substrates for liquid crystal displays, substrates for plasma displays, substrates for organic EL devices, substrates for FEDs (Field Emission Displays), substrates for optical displays, substrates for magnetic disks, substrates for magnetic optical disks, substrates for photomasks, or substrates for solar cells (hereinafter called simply substrates), along with pods, to and from an interior of a substrate treating apparatus, and for controlling transfer of the pods to and from a carrier transport system. The invention relates also to a substrate treating method, a substrate treating system, a method of operating a substrate treating system, a load port control apparatus, and a substrate treating system having the load port control apparatus.
(2) Description of the Related Art
Conventionally, a substrate treating system of this type includes a substrate treating apparatus, and a carrier transport system for transporting pods upon instructions of a host computer which performs overall control of the treating system. The substrate treating apparatus has a substrate treating unit, a pod storage and transport unit, a load port, and a load port control device.
The substrate treating unit carries out various types of treatment for substrates. The pod storage and transport unit is juxtaposed to the substrate treating unit for storing and transporting FOUPs (Front Opening Unified Pods) containing the substrates. The load port is juxtaposed to the pod storage and transport unit for receiving the FOUPs. The load port control device controls transfer of the FOUPs to and from the pod storage and transport unit and to and from the carrier transport system. The carrier transport system is an automated material handling system having automatic guided vehicles (AGV), or an overhead hoist transfer, which transfers the FOUPS to and from the load port. The host computer carries out controls relating to transportation of the pods through communication with the load port control device and the carrier transport system.
Generally, one substrate treating apparatus has a plurality of load ports. With an improvement in treatment efficiency of the substrate treating unit, the number of pods to be transported will increase. The efficiency of the substrate treating unit cannot be used to full advantage without reducing transport intervals of the pods by the carrier transport system. However, with this type of carrier transport system, a plurality of transport vehicles in the carrier transport system do not load the pods into one load port at the same time. In general use (standard), only one transport vehicle loads the pods into one load port. And under restrictions imposed by the layout of the carrier transport system, for example, the time taken for one transport vehicle to load the pods into one load port cannot be shortened to be less than a certain level. Consequently, transportation by the carrier transport system cannot keep up an expected pace, resulting in a problem of reduced treatment efficiency.
In the circumstances, a first apparatus has been proposed, which has the number of load ports increased in a height direction, with a corresponding increase in the running lane of the carrier transport system to two (see Patent Document 1, for example). Further, a second apparatus has been proposed, which provides a movable buffer adjacent a load port to serve as a temporary turnout for pods, so that the load port may be made vacant in a short time (see Japanese Unexamined Patent Publication No. 2010-192855, for example).
However, the conventional examples with such constructions have the following drawbacks.
The first conventional apparatus requires increases in the number of load ports and the number of running lanes of the carrier transport system. This poses a problem of increased apparatus cost.
The second conventional apparatus requires the special movable buffer provided adjacent the load port, which again poses a problem of increased apparatus cost.